SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cf0f436fa6a49d1aa01c628a6615c2f3e16a22d7136479765b24bbb4a69e84b' 
  AND token = 'FH3V8iDqa2jZZ3WwK9AiqG87y4hN3zJHa2mQdPI2qSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}